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EPR dosimetry in chemically treated fingernails.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
By using EPR measurements of radiation-induced radicals it is possible to utilize human fingernails to estimate radiation dose after-the-fact. One of the potentially limiting factors in this approach is the presence of artifacts due to mechanically induced EPR signals (MIS) caused by mechanical stress during the collection and preparation of the samples and the so-called background (non-radiation) signal (BKS). The MIS and BKS have spectral parameters (shape, g-factor and linewidth) that overlap with the radiation-induced signal (RIS) and therefore, if not taken into account properly, could result in a considerable ove...
Source: Radiation Measurements - August 1, 2007 Category: Physics Authors: Romanyukha A, Trompier F, Leblanc B, Calas C, Clairand I, Mitchell CA, Smirniotopoulos JG, Swartz HM Tags: Radiat Meas Source Type: journals

Protocol for emergency EPR dosimetry in fingernails.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
There is an increased need for after-the-fact dosimetry because of the high risk of radiation exposures due to terrorism or accidents. In case of such an event, a method is needed to make measurements of dose in a large number of individuals rapidly and with sufficient accuracy to facilitate effective medical triage. Dosimetry based on EPR measurements of fingernails potentially could be an effective tool for this purpose. This paper presents the first operational protocols for EPR fingernail dosimetry, including guidelines for collection and storage of samples, parameters for EPR measurements, and the method of dose a...
Source: Radiation Measurements - August 1, 2007 Category: Physics Authors: Trompier F, Kornak L, Calas C, Romanyukha A, Leblanc B, Mitchell CA, Swartz HM, Clairand I Tags: Radiat Meas Source Type: journals

Sample Tracking in an Automated Cytogenetic Biodosimetry Laboratory for Radiation Mass Casualties.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Chromosome aberration-based dicentric assay is expected to be used after mass casualty life-threatening radiation exposures to assess radiation dose to individuals. This will require processing of a large number of samples for individual dose assessment and clinical triage to aid treatment decisions. We have established an automated, high-throughput, cytogenetic biodosimetry laboratory to process a large number of samples for conducting the dicentric assay using peripheral blood from exposed individuals according to internationally accepted laboratory protocols (i.e., within days following radiation exposures). The com...
Source: Radiation Measurements - July 1, 2007 Category: Physics Authors: Martin PR, Berdychevski RE, Subramanian U, Blakely WF, Prasanna PG Tags: Radiat Meas Source Type: journals

Some more new etchants for CR-39 detector.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recently, several new etchants have been reported for CR-39 detector (Molten Ba(OH)2. 8H2O as an etchant for CR-39 detector, Radiat. Meas. 37 (2003) 205; Discovery of new etchants for CR-39 detector, Radiat. Meas. (2004)). We have made further progress in this direction and have unveiled two more new etchants which are reported in this article. CR-39 detectors were irradiated with fission fragments and alpha particles from a thin 252Cf disc source. The irradiated detectors were then etched in our newly introduced etching solutions as well as in conventionally used 6 M NaOH aqueous solution at 70 degrees C. The newly pr...
Source: Radiation Measurements - October 1, 2005 Category: Physics Authors: Matiullah , Rehman S, Rehman S, Mati N, Ahmad S Tags: Radiat Meas Source Type: journals

Nuclear fragmentation cross-sections of 400 A MeV 36Ar and 40Ar in collisions with light and heavy target nuclei.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We have measured fragmentation cross-sections of Ar projectile nuclei at beam energy of 400 A MeV using experimental set-ups with plastic nuclear track detectors and different targets. In this paper total charge changing cross-sections and elemental fragmentation cross-sections for the production of fragments with charges ZF > or = 7 in interactions with H, C, Al, Cu, Ag and Pb target nuclei are presented. The dependence of the cross-sections on the fragment charge number and target charge number are discussed. The experimental results are compared to predictions of semi empirical cross-section models. PMID: 160...
Source: Radiation Measurements - October 1, 2005 Category: Physics Authors: Iancu G, Flesch F, Heinrich W Tags: Radiat Meas Source Type: journals

Proton therapy analysis using the Monte Carlo method.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The range and straggling data obtained from the transport of ions in matter (TRIM) computer program were used to determine the trajectories of monoenergetic 60 MeV protons in muscle tissue by using the Monte Carlo technique. The appropriate profile for the shape of a proton pencil beam in proton therapy as well as the dose deposited in the tissue were computed. The good agreements between our results as compared with the corresponding experimental values are presented here to show the reliability of our Monte Carlo method. PMID: 16094775 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - October 1, 2005 Category: Physics Authors: Noshad H, Givechi N Tags: Radiat Meas Source Type: journals

Response of CR-39 to medium energy electron irradiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effect of 5-15 keV electron irradiation on the etch rate of CR-39 nuclear track detectors has been investigated for surface doses from 0.09 to 13.85 J/cm2. Even before etching, electrons produce a surface depression proportional to the surface dose raised to the power 0.78 +/- 0.01. Etch rate enhancement was observed in the surface region (about 4 micrometers deep) and was well approximated by a Gaussian function of depth. The depth and thickness of the etch rate enhancement increase with increasing electron energy, but are independent of dose. The maximum etch rate is proportional to the peak volumetric dose raise...
Source: Radiation Measurements - September 1, 2005 Category: Physics Authors: Wahl CG, McLean JG Tags: Radiat Meas Source Type: journals

Proton tracks and the formation of pores in poly[diethylene glycol bis-(allyl carbonate)]Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Modern dosimetry needs efficient detectors for registering light ions, especially light ions having energies of up to 10 MeV/amu. That is why this research pays attention to the development of materials for such a task. In this work, a CR-39 detector, which is the most efficient detector, was used. It was irradiated with low-energy protons. Using sensitive electrolytic etching and electron scanning microscopy, a complete analysis was carried out of the process of the formation of a pore starting from its opening to the final stage of its formation. The process of sequential track breakthroughs was observed. The data ob...
Source: Radiation Measurements - September 1, 2005 Category: Physics Authors: Oganessian VR, Trofimov VV, Danziger M, Dörschel B, Hermsdorf D, Orelovitch OL Tags: Radiat Meas Source Type: journals

Discovery of new etchants for CR-39 detector.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
After reporting the excellent etching properties of molten Ba(OH)2 8H2O as an etchant, we now report some more new and efficient etchants for CR-39 detector. CR-39 detectors were irradiated with fission fragments and alpha particles with a thin 252Cf source. The irradiated detectors were etched in a number of our newly introduced etching solutions as well as in conventionally used 6 M NaOH at 70 degrees C. The newly prepared etching solutions included NaOH/ethanol and NaOH/1-propanol. Processing conditions were optimized for these etchants. From fission and alpha track diameters, bulk etching velocity (VB), track etchi...
Source: Radiation Measurements - June 1, 2005 Category: Physics Authors: Matiullah , Rehman S, Rehman S, Zaman W Tags: Radiat Meas Source Type: journals

The angular dependence of an Si energy deposition spectrometer response at several radiation sources.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
An MDU-Liulin spectrometer based on an Si-diode was mainly used during the last few years with the goal to use them for measurements onboard aircraft. To investigate its ability to obtain such measurements, the detector was tested in some radiation reference fields, like 60Co and other photon beams, neutrons of an AmBe and 252Cf sources and in high-energy radiation fields at CERN. Due to the high geometrical asymmetry of the Si-diode semiconductor, an angular dependence of the response would be expected. This work presents analyses and discusses the results of angular dependence studies obtained at the different radiat...
Source: Radiation Measurements - June 1, 2005 Category: Physics Authors: Spurný F, Trompier F, Bottollier-Depois JF Tags: Radiat Meas Source Type: journals

Variation of long-lived free radicals responsible for the EPR native signal in bone of aged or diseased human females and ovariectomized adult rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this study was to gain insights into the variations seen in the electron paramagnetic resonance (EPR) spectroscopy of the native signals of teeth and bones used for retrospective dosimetry measurements. We determined that changes occur in the long-lived free radicals responsible for the native signal of cortical bone in aging or diseased human females and aged ovariectomized rats. This was done by measuring the magnitude of the broad (BC) and narrow (NC) components of the native EPR signal of bone following chemical extraction, aging, crushing and thermal annealing. Bone from the upper midshaft of femora...
Source: Radiation Measurements - June 1, 2005 Category: Physics Authors: Kenner GH, Brik AB, Liu G, Haskell EH, Hayes RB, Knight JA, Vajda EG, Miller SC, Jee WS, Barrus JK Tags: Radiat Meas Source Type: journals

Radiation measurement on the International Space Station.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380 km and inclination 51.6 degrees are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z > or = 2) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of dE/dx and during the last years it has already been successfully used on board the MIR station, Space Shuttles and "Kosmos" spacecrafts. An ...
Source: Radiation Measurements - February 1, 2005 Category: Physics Authors: Akopova AB, Manaseryan MM, Melkonyan AA, Tatikyan SSh, Potapov Y Tags: Radiat Meas Source Type: journals

Response of a Si-diode-based device to fast neutrons.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Semiconductor devices based on a Si-detector are frequently used for charged particle's detection; one application being in the investigation of cosmic radiation fields. From the spectra of energy deposition events in such devices, the total energy deposited by the radiation in silicon can be derived. This contribution presents the results of studies concerning the response of this type of detector to fast neutrons. First, the spectrum of energy deposition was established in fast neutron radiation fields with average energies from 0.5 to 50 MeV. It was found that these spectra vary significantly with the neutron energy...
Source: Radiation Measurements - February 1, 2005 Category: Physics Authors: Spurný F Tags: Radiat Meas Source Type: journals

Radiation exposure at ground level by secondary cosmic radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The contribution of the charged component of secondary cosmic radiation to the ambient dose equivalent H*(10) at ground level is investigated using the muon detector MUDOS and a TEPC detector surrounded by the coincidence detector CACS to identify charged particles. The ambient dose equivalent rate H*(10)T as measured with the TEPC/CACS is used to calibrate the MUDOS count rate in terms of H*(10). First results from long-term measurements at the PTB reference site for ambient radiation dosimetry are reported. The air pressure corrected dose rate shows, as expected, a strong correlation with the neutron count rate as me...
Source: Radiation Measurements - January 1, 2005 Category: Physics Authors: Wissmann F, Dangendorf V, Schrewe U Tags: Radiat Meas Source Type: journals

Dependence of irradiation temperature in the response of iron salts.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A potential dosimeter based on aqueous frozen solutions and solid-state salt are presented for the evaluation of the energy transferred during the interaction of high-energy radiation with matter at low temperature. The foundation of these dosimeters, both the solid state and the frozen solutions, is based on the measurement of the change of the iron oxidation state. The systems were irradiated with gamma radiation at different doses (up to 10 MGy), and at different temperatures (from 77 to 298 K). The irradiated samples were analysed by UV-spectroscopy and Mössbauer spectroscopy. A theoretical model was developed...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Martínez T, Lartigue J, Frias D, Sanchez-Mejorada G, Negrón-Mendoza A, Ramos-Bernal S Tags: Radiat Meas Source Type: journals

Dosimetric properties of the newly developed KLT-300 (LiF:Mg,Cu,Na,Si) TL detector.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The dosimetric properties of the newly developed KLT-300 (KAERI LiF:Mg,Cu,Na,Si TL detector) in KAERI (Korea Atomic Energy Research Institute) were investigated. The sensitivity of the TL detector was about 30 times higher than that of the TLD-100 by light integration. In the study of the dose linearity of the detector, the dose response was very linear up to 10 Gy and a sublinear response was observed at higher doses. The energy response of the detector was studied for photon energies from 20 to 662 keV. The results show that a maximum response of 1.004 at 53 keV and a minimum response of 0.825 at 20 keV were observed...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Lee JI, Kim JL, Chang SY, Chung KS, Choe HS Tags: Radiat Meas Source Type: journals

Dependence of thermoluminescence response of calcium sulphate activated by dysprosium on the temperature irradiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Radiation dosimetry is a very important issue in space research and in experiments that try to simulate chemical processes that may occur in cometary nucleus, interstellar grains, and other extraterrestrial environments, due to their irradiation by cosmic rays. The temperature effect is an important factor that has not been considered in many of these experiments. In this work, this effect was studied in TLD dosimeters exposed to gamma rays. The irradiations were done from 77 to 298 K in a gamma cell unit with a dose rate of 1.0 Gy/s. Results obtained for CaSO4:Dy show that there is a considerable effect in the evaluat...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Hernández A, Cruz-Zaragoza E, Negrón-Mendoza A, Ramos-Bernal S Tags: Radiat Meas Source Type: journals

LiF:Mg,Ti (MTT) TL detectors optimised for high-LET radiation dosimetry.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The properties of LiF:Mg,Ti (distributed as, e.g., TLD-100 or MTS-N), the most frequently used thermoluminescent detector, have been optimised for measurements of sparsely ionizing radiation (gamma rays), typically encountered in radiation protection or clinical dosimetry. However, these detectors need also to be applied in conditions of mixed-field dosimetry with a high-LET component, such as those encountered in heavy ion beams or in space. At the Institute of Nuclear Physics in Kraków a new type of LiF:Mg,Ti detector (named MTT) has been recently developed through modification of its dopant composition. This co...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Bilski P, Budzanowski M, Olko P, Mandowska E Tags: Radiat Meas Source Type: journals

The response of thermally and optically stimulated luminescence from Al2O3:C to high-energy heavy charged particles.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The thermoluminescence (TL) and optically stimulated luminescence (OSL) response of Al2O3 dosimeters to high-energy heavy charged particles (HCP) has been studied using the heavy ion medical accelerator at Chiba, Japan. The samples were Al2O3 single-crystal chips, of the type usually known as TLD-500, and Luxel(TM) dosimeters (Al2O3:C powder in plastic) from Landauer Inc. The samples were exposed to 4He (150 MeV/u), 12C (400 MeV/u), 28Si (490 MeV/us) and 56Fe (500 MeV/u) ions, with linear energy transfer values covering the range from 2.26 to 189 keV/micrometers in water and doses from 1 to 100 mGy (to water). A 90Sr/9...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Gaza R, Yukihara EG, McKeever SW Tags: Radiat Meas Source Type: journals

Response of thermoluminescent detectors to charged particles and to neutrons.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Thermoluminescent detectors (TLDs) are widely used for the dosimetry of photons and electrons. They are less used for the radiation with higher linear energy transfer (LET). One of the reasons for that is that their TL relative efficiency eta decreases for the most of them with increasing LET. The paper presents first a review of author's experimental results in which eta was established for charged particles having LET of the order from 1 to 100 keV/micrometers in tissue. Among TLDs studied were known materials like LiF:Mn; Ti; Al-P glass; CaSO4:Dy; Al2O3:Na; and Al2O3:C. It was found that the dependence of their eta ...
Source: Radiation Measurements - August 1, 2004 Category: Physics Authors: Spurný F Tags: Radiat Meas Source Type: journals

Effect of high-dose irradiation on the optically stimulated luminescence of Al2O3:C.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper examines the effect of high-dose irradiation on the optically stimulated luminescence (OSL) of Al2O3:C, principally on the shape of the OSL decay curve and on the OSL sensitivity. The effect of the degree of deep trap filling on the OSL was also studied by monitoring the sensitivity changes after doses of beta irradiation and after step-annealing of samples previously irradiated with high doses. The OSL response to dose shows a linear-supralinear-saturation behavior, with a decrease in the response for doses higher than those required for saturation. This behavior correlates with the sensitivity changes obse...
Source: Radiation Measurements - June 1, 2004 Category: Physics Authors: Yukihara EG, Whitley VH, McKeever SW, Akselrod AE, Akselrod MS Tags: Radiat Meas Source Type: journals

A new ESR dosimeter based on bioglass material.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bioglass (Bio-G) samples were irradiated with 60Co gamma-rays to study radicals for dosimetric materials with electron spin resonance (ESR). The ESR spectrum of Bio-G is characterized by two main signals. The first signal at g approximately = 4.3 corresponds to Fe3+ impurities and the second signal at g approximately = 2.0130 with line-width 10.85 G is ascribed as a hole center. The gamma-ray dose response and thermal stability were studied to establish the suitability of bioglass as an ESR dosimeter. A radical formation efficiency, G-value, of 0.53 +/- 0.11 was obtained. The lifetime of radicals and the activation ene...
Source: Radiation Measurements - June 1, 2004 Category: Physics Authors: Hassan GM, Sharaf MA, Desouky OS Tags: Radiat Meas Source Type: journals

Effect of beta-particles on the retinal chromophore in bacteriorhodopsin of Halobacterium salinarium.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bacteriorhodopsin (bR) is an attractive intelligent material. Understanding the mechanism of its light-driven proton pumping outward the cell implicates it in many technical applications, particularly, in what is called optical computers, and the biotechnology is waiting for this promised biological molecule. An ionizing radiation source handling could be computerized in radiation fields. The computer containing such biological material will not be out of reach of the fields of ionizing radiation. So it is interesting to report on the working of such biological computer if it is subjected to ionizing radiation. The fun...
Source: Radiation Measurements - April 1, 2004 Category: Physics Authors: Mostafa HI Tags: Radiat Meas Source Type: journals

Optically stimulated luminescence and thermoluminescence efficiencies for high-energy heavy charged particle irradiation in Al2O3:C.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The thermally and optically stimulated luminescence (TL and OSL) response to high energy heavy-charged particles (HCPs) was investigated for two types of Al2O3:C luminescence dosimeters. The OSL signal was measured in both continuous-wave (CW) and pulsed mode. The efficiencies of the HCPs at producing TL or OSL, relative to gamma radiation, were obtained using four different HCPs beams (150 MeV/u 4He, 400 MeV/u 12C, 490 MeV/u 28Si, and 500 MeV/u 56Fe). The efficiencies were determined as a function of the HCP linear energy transfer (LET). It was observed that the efficiency depends on the type of detector, measurement ...
Source: Radiation Measurements - February 1, 2004 Category: Physics Authors: Yukihara EG, Gaza R, McKeever SW, Soares CG Tags: Radiat Meas Source Type: journals

Concepts and approaches to in situ luminescence dating of Martian sediments.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this paper we present the concept of a robotic instrument for in situ luminescence dating of near-surface sediments on Mars. The scientific objectives and advantages to be gained from the development of such an instrument are described, and the challenges presented by the Mars surface environment to the design and operation of the instrument are outlined. PMID: 12856693 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - August 1, 2003 Category: Physics Authors: McKeever SW, Banerjee D, Blair M, Clifford SM, Clowdsley MS, Kim SS, Lamothe M, Lepper K, Leuschen M, McKeever KJ, Prather M, Rowland A, Reust D, Sears DW, Wilson JW Tags: Radiat Meas Source Type: journals

Transmission measurement based on STM observation to detect the penetration depth of low-energy heavy ions in botanic samples.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The penetration depth of low-energy heavy ions in botanic samples was detected with a new transmission measurement. In the measurement, highly oriented pyrolytic graphite (HOPG) pieces were placed behind the botanic samples with certain thickness. During the irradiation of heavy ions with energy of tens of keV, the energetic particles transmitted from those samples were received by the HOPG pieces. After irradiation, scanning tunneling microscope (STM) was applied to observe protrusion-like damage induced by these transmitted ions on the surface of the HOPG. The statistical average number density of protrusions and the...
Source: Radiation Measurements - February 1, 2003 Category: Physics Authors: Liu F, Wang Y, Xue J, Wang S, Du G, Zhao W Tags: Radiat Meas Source Type: journals

Sensitivity of whole human teeth to fast neutrons and gamma-rays estimated by L-band EPR spectroscopy.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper reports the first attempt to use L-band spectroscopy for estimating the sensitivity of whole teeth to fast neutrons and gamma-rays. Three teeth were successively irradiated first with fast neutrons with a wide energy spectrum (mean energy around 30 MeV) up to approximately 160 Gy and then with gamma-rays up to approximately 14 Gy. After each irradiation, L-band (approximately 1 GHz) EPR spectra of each whole tooth surrounded by the surface-coil resonator were recorded, yielding a single composite line principally due to CO2- and native radicals. The sensitivities are estimated by the slopes of the linear dos...
Source: Radiation Measurements - December 1, 2002 Category: Physics Authors: Zdravkova M, Denis JM, Gallez B, Debuyst R Tags: Radiat Meas Source Type: journals

In vitro cell irradiation systems based on 210Po alpha source: construction and characterisation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
One way of studying the risk to human health of low-level radiation exposure is to make biological experiments on living cell cultures. Two 210Po alpha-particle emitting devices, with 0.5 and 100 MBq activity, were designed and constructed to perform such experiments irradiating monolayers of cells. Estimates of dose rate at the cell surface were obtained from measurements by a PIPS alpha-particle spectrometer and from calculations by the SRIM 2000, Monte Carlo charged particle transport code. Particle fluence area distributions were measured by solid state nuclear track detectors. The design and dosimetric characteris...
Source: Radiation Measurements - December 1, 2002 Category: Physics Authors: Szabo J, Feher I, Palfalvi J, Balashazy I, Dam AM, Polonyi I, Bogdandi EN Tags: Radiat Meas Source Type: journals

Equivalent dose measurements on board an Armenian Airline flight and Concorde (correction of Concord) (9-17 km).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The results of investigations of the neutron component (E=1-10 MeV) of cosmic radiation on board the "Armenian Airlines" aircrafts using nuclear photoemulsion are presented. The emulsions were exposed on the flights from Yerevan to Moscow, St.-Petersburg, Beirut, Athens, Frankfurt, Amsterdam, Paris and Sofia, and on Concord supersonic flights from Paris to New York. The dependence of the neutron fluxes, and on absorbed and equivalent doses on the flight parameters were investigated. On the flights of the supersonic Concord, with an altitude of 17 km, the neutron fluxes were essentially higher in comparison to those mea...
Source: Radiation Measurements - December 1, 2002 Category: Physics Authors: Akopova AB, Melkonyan AA, Tatikyan SSh, Capdevielle JN Tags: Radiat Meas Source Type: journals

Response of a tissue equivalent proportional counter to neutrons.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The absorbed dose as a function of lineal energy was measured at the CERN-EC Reference-field Facility (CERF) using a 512-channel tissue equivalent proportional counter (TEPC), and neutron dose equivalent response evaluated. Although there are some differences, the measured dose equivalent is in agreement with that measured by the 16-channel HANDI tissue equivalent counter. Comparison of TEPC measurements with those made by a silicon solid-state detector for low linear energy transfer particles produced by the same beam, is presented. The measurements show that about 4% of dose equivalent is delivered by particles heavi...
Source: Radiation Measurements - December 1, 2002 Category: Physics Authors: Badhwar GD, Robbins DE, Gibbons F, Braby LA Tags: Radiat Meas Source Type: journals

Comparison of graphite, aluminum, and TransHab shielding material characteristics in a high-energy neutron field.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal e...
Source: Radiation Measurements - December 1, 2002 Category: Physics Authors: Badhwar GD, Huff H, Wilkins R, Thibeault S Tags: Radiat Meas Source Type: journals

Dosimetry and microdosimetry characteristics measured on board the MIR station during the 28th basic expedition.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Three types of detectors were used onboard the MIR station during the 28th base expeditions to characterise the radiation field: a linear energy transfer (LET) spectrometer was used to establish the LET spectrum between 7 and 700 keV/micrometers corresponding mostly to secondary charged particles; a set of thermoluminescent detectors was used to characterise the low LET component of the onboard radiation field; and Si-diodes were installed to determine the contribution to the exposure due to fast neutrons. It was found out that the LET spectrum from secondary particles between 7 and 700 KeV/micrometers does not depend ...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Spurny F, Dudkin VE Tags: Radiat Meas Source Type: journals

Measurements of neutron fluxes with energies from thermal to several MeV in near-Earth space: SINP results.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Neutron measurement results obtained at SINP MSU since 1970 are presented. These measurements were made using techniques based on neutron moderation and subsequent detection in a Li6I(Eu) crystal or a He3 coronal counter. The measurements were mainly carried out in orbits with inclination of 52 degrees and altitudes of 200-450 km. The spatial and angular distributions of the measured neutron fluxes were studied. The albedo neutron flux was estimated according to the count rate difference for opposite detector orientations towards Earth and away from it. This flux is comparable to the local neutron flux outside the Braz...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Shavrin PI, Kuzhevskij BM, Kuznetsov SN, Nechaev OY, Panasyuk MI, Ryumin SP, Yushkov BY, Bratolyubova-Tsulukidze LS, Lyagushin VI, Germantsev YL Tags: Radiat Meas Source Type: journals

Verification of methods of MIR-station's crew members personal dose estimation based on radiation monitoring data.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
During the flight of the main missions on board the MIR station the individual doses of the crew members and the dose inside the core module was measured by the ID-3M package and R-16 dosimeter, respectively. Comparison of the skin dose measured by ID-3M unit and calculated by the transmission coefficient method on the basis of R-16 data in each of 23 main missions permits estimation of the systematic error of the transmission coefficient method. The mean value of this error is equal to 32%. PMID: 12442750 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Petrov VM Tags: Radiat Meas Source Type: journals

Radiation dose measurements aboard the Mir using the R-16 instrument.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 12442749 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Mitricas VG, Tsetlin VV, Teltsov MV, Shumshurov VI Tags: Radiat Meas Source Type: journals

Energy spectrum of 50-250 MeV/nucleon iron nuclei inside the MIR space craft.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Stacks of CR-39 plastic nuclear track detectors were mounted inside the MIR spacecraft during the EUROMIR95 space mission for a period of 6 months. This long exposure time resulted in a large number of tracks of HZE-particles in the detector foils. All trajectories of stopping iron nuclei could be reconstructed by optimizing the etching conditions so that an automatic track measurement using image analysis techniques was possible. We found 185 stopping iron nuclei and used the énergy-range relation to calculate their energies at the stack surface. The measured spectrum of iron nuclei inside the MIR station is comp...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Gunther W, Leugner D, Becker E, Heinrich W, Reitz G Tags: Radiat Meas Source Type: journals

Dose equivalents inside the MIR Space Station measured by the combination of CR-39 plates and TLDs and their comparison with those on Space Shuttle STS-79, -84 and -91 missions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In 1997, four dosimeter packages, each of which contains two CR-39 plates and 18 TLDs (Mg2SiO4:Tb), were placed inside the MIR Space Station and flew on an orbit with an inclination angle of 51.6 degrees and an altitude of approximately 400 km for 40 days. We estimated the absorbed doses, dose equivalents and effective quality factors during the flight by combining CR-39 data and TLD data. We then compared these results to those obtained with the same analysis method from the dosimeter packages on board Space Shuttle missions STS-79, -84 and -91 that flew along the same orbit. Finally, the differences between our resul...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Doke T, Hayashi T, Kikuchi J, Nagaoka S, Nakano T, Takahashi S, Tawara H, Terasawa K Tags: Radiat Meas Source Type: journals

Data failures in the "Riabina-2" experiment on MIR orbital station.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Experimental data about high-energy particle fluxes obtained in 1990-2000 in the Riabina-2 experiment on board MIR orbital station are analyzed in the sense of data failures. There are two types of failure. The first type is represented as sharp positive or negative spikes on the relatively smooth time profiles of the particle fluxes. The second type is randomly distributed data gaps with durations of up to tens minutes. These two kinds of the data failures are formalized in the form of "failure occurrence probability" (FOP). The comparison analysis of the FOP with solar activity, solar wind conditions and geomagnetic ...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Dmitriev AV, Guilfanov II, Panasyuk MI Tags: Radiat Meas Source Type: journals

The high-energy proton fluxes in the SAA observed with REM aboard the MIR orbital station.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
During two years, from November 1994 to 1996, the particle detector REM measured the highly energetic electron and proton environment at the outside of the MIR orbital station. Using mission averaged data we investigate various aspects of the proton fluxes in the SAA. Comparison with the radiation belt model AP8 reveal important differences. PMID: 12442745 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Buhler P, Zehnder A, Kruglanski M, Daly E, Adams L Tags: Radiat Meas Source Type: journals

TEPC measurements obtained on the Mir space station.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Measurements of the radiation environment inside the Mir space station were performed with a tissue equivalent proportional counter (TEPC) during the Antares mission in 1992, and over a long period following it. Interesting results concerning radiation measurements show (a) the South Atlantic Anomaly crossing, (b) the increase of radiation near the poles, and (c) the effects of solar particle events (the most important one occurring in early November 1992). This data also provides information about the dose and the quality factor of the radiation to which the cosmonauts were exposed during different missions. These dat...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Bottollier-Depois JF, Siegrist M, Petrov VM, Shurshakov VV, Bengin V, Koslova SB Tags: Radiat Meas Source Type: journals

The properties of gamma-radiation and high-energy neutron fluxes in "MIR" station orbit.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The study of radiation background components in the near-Earth space is very important for different branches of space research, in particular for space dosimetry and for the planning of gamma-astronomy experiments. Detailed information on the neutral components (gamma-quanta, neutrons) of background radiation was obtained during the Grif-1 experiment onboard Mir orbital station (OS). The measurements of fluxes of 0.05-50 MeV gamma-quanta and >30 MeV neutrons with a large area instrument (approximately 250 cm2 for gamma-quanta, approximately 30 cm2 for neutrons) as well as corresponding charged particle measurements...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Bogomolov AV, Bogomolov VV, Denisov YI, Logachev YI, Svertilov SI, Kudryavtsev MI, Lyagushin VI, Ershova TV Tags: Radiat Meas Source Type: journals

Passive dosimetry aboard the Mir Orbital Station: external measurements.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper reports results from the first measurements made on the exterior of a LEO spacecraft of mean dose equivalent rate and average quality factor as functions of shielding depth for shielding less than 1 g/cm2 Al equivalent. Two sets of measurements were made on the outside of the Mir Orbital Station; one near solar maximum in June 1991 and one near solar minimum in 1997. Absorbed dose was measured using stacks of TLDs. LET spectrum from charged particles of LET infinity H2O > o r= 5keV/micrometers was measured using stacks of CR-39 PNTDs. Results from the TLD and PNTD measurements at a given shielding depth w...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Benton ER, Benton EV, Frank AL Tags: Radiat Meas Source Type: journals

Passive dosimetry aboard the Mir Orbital Station: internal measurements.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum fr...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Benton ER, Benton EV, Frank AL Tags: Radiat Meas Source Type: journals

Dosimetry inside MIR station using a silicon detector telescope (DOSTEL).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The dosimetry telescope (DOSTEL) was flown on the MIR orbital station during October 1997-January 1998. The mission average contributions to the absorbed dose rates (in water) were 126 +/- 4 microGy/d and 121 +/- 13 microGy/d for the GCR and the SAA component, respectively. The mean quality factors (ICRP60) deduced from the LET-spectra are 3.5 +/- 0.2 (GCR) and 1.3 +/- 0.1 (SAA). Separate LET spectra and temporal variations of the absorbed dose rates and of the mean quality factors are presented for these two radiation components as well as for solar energetic particles of the November 6, 1997 event. PMID: 12440435...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Beaujean R, Kopp J, Burmeister S, Petersen F, Reitz G Tags: Radiat Meas Source Type: journals

The high-energy heavy-particle fluences in the orbits of manned space stations.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The results are presented of measurements high-energy particles in a customary manned space station orbit (a 350-450-km altitude, a 51.6 degrees inclination; Salyut-6 and 7, MIR). The particles were recorded by the chambers composed of the Lavsan (polyethyleneterephtalate) solid-state nuclear track detector layers mounted outside a spacecraft for 1-3 years. A high resolution has been attained in the charge and energy spectra of 30-200 MeV/n Fe group particles. The results of measuring the particle fluxes in the space station orbits are used to restore the initial particle energy spectra in terms of the models that desc...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Baranov DG, Dergachev VA, Gagarin YF, Lyagushin VI, Nymmik RA, Panasyuk MI, Solov'ev AV, Yakubovskii EA Tags: Radiat Meas Source Type: journals

Radiation measurements on the Mir Orbital Station.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Radiation measurements made onboard the MIR Orbital Station have spanned nearly a decade and covered two solar cycles, including one of the largest solar particle events, one of the largest magnetic storms, and a mean solar radio flux level reaching 250 x 10(4) Jansky that has been observed in the last 40 years. The cosmonaut absorbed dose rates varied from about 450 microGy day-1 during solar minimum to approximately half this value during the last solar maximum. There is a factor of about two in dose rate within a given module, and a similar variation from module to module. The average radiation quality factor during...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Badhwar GD, Atwell W, Reitz G, Beaujean R, Heinrich W Tags: Radiat Meas Source Type: journals

Dose measurements in space by the Hungarian Pille TLD system.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensio...
Source: Radiation Measurements - October 1, 2002 Category: Physics Authors: Apathy I, Deme S, Feher I, Akatov YA, Reitz G, Arkhanguelski VV Tags: Radiat Meas Source Type: journals

Radiation on the Mir Orbital Station. Special issue.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Authors: PMID: 12440427 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - October 1, 2002 Category: Physics Tags: Radiat Meas Source Type: journals

Analysis of the calibration results obtained with Liulin-4J spectrometer-dosimeter on protons and heavy ions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We are developing a portable dosimeter (Liulin-4J) based on a silicon semiconductor detector for use in measuring the absorbed dose from primary or secondary cosmic rays to astronauts and airplane crews. The dosimeter can measure not only the flux and dose rate, but also the deposited energy spectrum for silicon in per unit time. In order to calibrate the dosimeter, we have carried out exposures at the NIRS cyclotron and HIMAC heavy ion synchrotron facilities. We obtained a detector response function for using in measuring energy deposition and LET. PMID: 11841107 [PubMed - indexed for MEDLINE]
Source: Radiation Measurements - April 1, 2002 Category: Physics Authors: Uchihori Y, Kitamura H, Fujitaka K, Dachev TP, Tomov BT, Dimitrov PG, Matviichuk Y Tags: Radiat Meas Source Type: journals

LET distributions from CR-39 plates on Space Shuttle missions STS-84 and STS-91 and a comparison of the results of the CR-39 plates with those of RRMD-II and RRMD-III telescopes.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The LET distributions during the Space Shuttle missions STS-84 (altitude 270-412 km, average 375 km; inclination angle, 51.6 degrees) and STS-91 (altitude 328-397 km, average 373 km; inclination angle, 51.6 degrees) were measured using CR-39 plastic nuclear track detectors. A correction for the dip-angle dependence of the track-formation sensitivity of the CR-39 plates was applied to the data analysis. The absorbed doses and the dose equivalents around RRMD Detector Units, estimated from the LET distributions in the LET region of 4-200 keV/micrometers, fluctuated with standard deviations of +/- 21% to +/- 35% in both f...
Source: Radiation Measurements - April 1, 2002 Category: Physics Authors: Tawara H, Doke T, Hayashi T, Kikuchi J, Kyan A, Nagaoka S, Nakano T, Takahashi S, Terasawa K, Yoshihira E Tags: Radiat Meas Source Type: journals